1. Field of the Invention
The invention relates to a tape-like packaging element, in particular a strapping tape or harvesting twine made from a polyester-based plastic tape, wherein at least one splicing inhibitor is contained in the plastic tape.
2. Description of the Related Art
Strapping tapes are usually made of polyesters or polyolefins in an extrusion process and subsequently stretched. Owing to the alignment of the molecules during the stretching process they have a predisposition to splicing, i.e. the formation of tears in tape direction. Owing to the embrittlement of plastics at lower temperatures, in particular below 5° C., the splicing tendency is increased further. To reduce the splicing tendency splicing inhibitors are usually added to the compounds for producing strapping tapes. Previously used splicing inhibitors have not helped sufficiently to reduce embrittlement at low temperatures.
From WO 03/087200 A1 a packaging tape is known, which consists up to more than 92 wt. % of a polyester and less than a total of 8 wt. % of an additive with a polyolefin base and additional additives, wherein the proportion of polyolefin additive is less than 3 wt. %. As additional additives also polystyrene-based elastomers are used in a proportion of between 0.5 wt. % and 2 wt. %. By adding polyolefin the longitudinal predisposition to splicing should be reduced. Likewise the styrene elastomers are intended to contribute to a reduction of this splicing tendency.
The use of styrene-butadiene rubber in proportions of up to 25 wt. % in a polyethylene band is also known from DE 20 37 398 A1, although in this document the purpose of the additive is not indicated.
DE 27 27 356 A1 describes a binding tape which is made from a heat-curable and thermoplastic resin, wherein the resins are derived from the same monomers, so that the two resins have a chemical affinity to one another, and wherein the heat-curable resin is an unsaturated polyester resin cross-linked with styrene. The thermoplastic resin can be an acrylonitrile-butadiene-styrene-mixed polymerizate or an acrylonitrile-styrene-mixed polymerizate. In this way a binding tape of sufficient strength should be produced which is comparable with a steel band, which has high tensile strength and low expansion as well as low creep behavior, and which can be joined easily and securely at the ends. In this case the thermoplastic resin forms the outer layer of the binding tape and the heat-curable resins forms the core.